Here are (some of) the results of my experimenting with "re-tuning"
bagpipe midifiles to match the temperament of real bagpipes.
I used a Ruby script to add a pitchbend event to each (chanter) note,
so that the resulting note frequencies should match "MacNeill" tuning.
[And see the bottom of the page for another script that does this for
live playing...]

Most of the files use the GM Bassoon voice as the "Bagpipe", but I've
included a couple with the GM Bagpipe as well.
The original 'Scotland the Brave' from the other site uses a Clarinet
rather than the Bassoon, but the retuned file is switched to Bassoon too.

I see that Jeremy has posted a link to this page, so perhaps I should
add a little more info for those arriving from that direction. The tuning
table in the script was derived from the table of tunings in
Ewan Macpherson's page on the topic. I chose the 'MacNeill' offsets
(cents from Equal Temerament), which may not have been the best. If you're
playing with it, you can easily adjust the table to your liking.

(The midifiles I converted were chosen pretty much at random — not
for any reasons of taste!)

All these have the same adjusted tuning except for the unretuned originals.

from 'Bagpipe Midi Files' site (http://www.cs.uleth.ca/~kaminski/midi/)

"Scotland the Brave"

Here's a zip of the script itself. It includes a (hopefully adequate)
README, and the necessary 'midifile.rb' utility module.:

pipebend.zip[Please note -- midifile.rb as supplied won't work in Ruby 1.9
(because of a drastic change they've made!). See the link below to the
midifile_rb page itself for the reason and a fix.]

There is a main page for
midifile.rb where you can
find a fuller description and some other utilities that use it.

...And one more thing...(:-)

It dawned on me that it's fairly easy in Linux to connect a live MIDI
stream from an input device to the stdin of a program, and similarly to
connect the output stream of the program to drive a MIDI device.
So I developed another Ruby script that does in real-time approximately
what the above script does for files. You can send MIDI from your keyboard
to the script and have it send appropriately 'bent' notes to a device
mimicking a bagpipe. Here is bagpipe.rb —
directly downloadable. It needs 'midifile.rb' too, which
you can get from either the other script zip-file or the above page link.